This invention relates to a control for typing timing in a reciprocative typing system.
A typing unit or apparatus is an end unit for printing out the processed result in data processors such as a personal computers, work processors, and the like. The need for such devices has quickly developed as office automation has spread. A need exists to improve the typing speed by improving process speed in the data processor.
Reciprocative typing mechanisms for typing the letter in reciprocal motion improve typing speed. Conventionally, reciprocative typing units are designed so that typing timing signals are generated in response to a distance between typings by a linear scale mounted along a travelling path of an encoder or typing head rotatable through an angle of 360.degree. in one reciprocal motion in association with movement of the typing head. Each letter is typed in response to a typing timing signal. A time lag to some extent is, however, inevitably produced between the signal and the typing due to characteristics of the typing head. As a result and as shown in FIGS. 1 and 2, even if the typing timing signal is generated when the head is at a position A the actual typing is made at a position A +.alpha. ahead of A due to mechanical delay. Similarly, when the typing timing signal is generate at A in rearward movement typing occurs at a point A-.alpha.. Unless compensated this produces typing with dots in different lines offset from each other different in to-and-fro motion. The conventional reciprocative typing apparatus has been therefore adapted to provide the typing timing signal earlier by an interval of .alpha., thereby mating each dot in forward direction with a corresponding dot in rearward direction.
The reciprocative typing apparatus as described above must be adjusted from time to time to alter letter spacing. However, adjustment in the forward direction produces incorrect typing positions in the rearward direction.
It is, therefore, an object of the invention to provide a reciprocative typing control system in which adjustment of typing spacing in reciprocation is automatic.
To this end, in the reciprocation typing control system according to the invention typing timing signals are generated at intervals shorter than the distance between the positions where typing is made, and the positions where type signals are delivered in to-and-fro motion can shift apart to adjust spacing between characters as desired.